The present invention generally relates to the field of bone fusion and, more particularly, to a system and method for performing bone fusion.
Spinal fusion is one method for treating spinal fractures and other injuries and diseases of the spine. Spinal fusion is a procedure performed by linking the two vertebras spanning the cartilaginous disc. The fusion procedure thereby either repairs the broken bone or eliminates the degenerated joint.
Spinal fusion is one method for treating spinal fractures. Spinal fusion is a procedure performed by linking the two vertebras spanning the cartilaginous disc. The fusion procedure thereby either repairs the broken bone or eliminates the degenerated joint.
Postero-lateral fusion is the most common type of spinal fusion operation that is performed. The process of postero-lateral fusion usually begins with the harvesting and handling of a bone graft and the preparation of a recipient transverse processes using a drill or a sharp awl. Typically, the bone graft is harvested within no more than 30 minutes of planned use thereby increasing the importance of efficiency during the surgical procedures. The graft also is kept moist in a saline or blood-soaked sponge before use.
The second step in postero-lateral fusion is the preparation of the recipient bed. The fusion bone to be placed in the fusion bed morcellated, either by hand or with a bone mill. An assistant then retracts the large muscle bundles in the back to expose the transverse processes and the postero-lateral space.
Areas of the recipient bed where there is planned fusion should be decorticated, which allows contact of the graft with cancellous bone while avoiding weakening the structure of the recipient bed with overzealous destruction of the cortical bone. It is imperative that preparation of the recipient bed be undertaken with utmost care because it protects the viability of the tissues that will serve as the primary source of the cellular components required for fusion. After the recipient fusion bed has been decorticated, the surgeon then deposits the morcellated fusion bone into the space piece by piece.
There are many drawbacks with current fusion methodologies. For example, in some cases the fusion bone is broken into small pieces by hand. This can be manually fatiguing and difficult for the surgical assistant. Additionally, it can occupy the surgical assistant and therefore impede their ability to assist the surgeon with the ongoing surgery.
U.S. Pat. No. 6,824,087 issued on Nov. 30, 2004, and is entitled “automatic bone mill.” Column 2, lines 31-34 and column 6, lines 29-32 of the patent state that an opening in a bone mill through which human bone is inserted into the bone mill can also be used to connect to a device such as a syringe for receiving milled bone from the bone mill. The content of this patent is incorporated by reference into this application as if fully set forth herein.
The device disclosed in the '087 patent has drawbacks. For example, by requiring a user to affix a syringe to the same opening in which bone is inserted into the device, a time delay is necessarily introduced before the milled bone can be inserted into a patient, which can have deleterious effects on the efficacy of the fusion procedure. Additionally, for example, the '087 patent contains no disclosure as to the ability to simultaneously use different sized syringes to withdraw milled bone and then simultaneously deposit the milled bone at different surgical sites that have different size requirements. It is important to minimize the time from when bone is harvested to when it is deposited at a surgical site, which is something that is not taught by the '087 patent.
Another drawback with some current procedures is the manner in which the recipient bed is prepared. The drill or awl used to prepare the transverse process must be placed with great accuracy to avoid injury to the surrounding soft-tissue structures. This requires greater effort at retracting the paraspinous muscle bundles that cover the bone. This process can be difficult and may result in greater post-operative discomfort to the patient.
Additionally, the current manner in which the bone is placed onto the recipient bed has a number of drawbacks. For example, under a current method, the assistant must perform the lengthy and arduous task of retraction of the patient's muscle bundles. Additionally, the bit by bit method of bone placement is exacerbating to the surgeon, and often results in a diminished and inadequate volume of bone placed into the gutter.